February 23rd, 2020

The 6mm-223 — A Wildcat Worth Considering

6mm 223 sinclair

Intro: Ron Dague wanted a new gun that was similar to his trusty .223 Rem rifle, but which fired 6mm bullets. There is a superb choice of bullets in this caliber, and Ron found that the 95gr Berger VLD could be driven to a healthy 2,604 fps by the small .223 Rem case. This 6mm wildcat based on the common .223 Rem offers excellent accuracy and very low recoil — something very important in the cross-the-course discipline. In addition, Ron’s 95gr load with Reloder 15 delivered an ES of just 4 fps over ten shots. That exceptionally low ES helps achieve minimal vertical dispersion at 600 yards.

6mm 223 Across the course McMilland stock Ron Dague Sinclair InternationalBy Ron Dague, Sinclair Reloading Tech
From Sinclair’s GunTech Articles Archive

I already had a .223 Remington match rifle, and I wanted the 6mm-223 to be as close to the same as I could make it. I installed the barreled action in a wood 40X stock to work up load data and work out any magazine feeding issues. While I was working on that, I looked for a McMillan Baker Special stock and finally found one to finish this project. I bedded the action and stock, then took the rifle to the range to check zeros on the sights and scope. I was surprised that I didn’t have to change anything on the sights. I thought changing the stock would cause sight changes. The thought went through my head, “Maybe the 40X stock isn’t all that bad”.

Here’s line-up of 6mm bullets. The Berger 95gr VLD is in the middle.
berger 6mm bullet hornady sierra line up 6mm 233

I took the new rifle to the first match of the year, a National Match Course match, and my off-hand score was 83, rapid sitting 95, rapid prone 95, and slow fire prone 197 — for total aggregate 470. This may not be my best work, but on match day the wind was blowing about 15 mph and the temp was around 40° F, with rain threatening. This was a reduced course of fire — we shot at 200 and 300 yards on reduced targets.

I used 70gr Berger bullets for this match, loaded in Remington brass with 25 grains of VihtaVuori N540 and Federal 205M primers. When I worked up loads for this rifle, N540 gave the best accuracy with the best extreme spread — 2,950 fps with an extreme spread of 20 fps on a 10-shot string. The load for 600 yards was with a 95gr Berger VLD bullet, with 23.0 grains of Reloder 15, Lapua cases, and the same Federal 205M primers. This load is 2,604 fps, with an extreme spread of 4 fps over a 10-shot string. I’ve shot this load at several 3×600 yard matches, and the accuracy has proven to be very good. At the last 3×600 match, my scores were as follows: 199-10x and 198-11X with scope, and 193-10X with iron sights. Best 600-yard score so far with iron sights was 198-12X.

6mm-223 Rem Rifle Specifications: 700 BDL action and floor plate, Bartlein 6mm 1:8″ twist, McMillan Baker Special stock in Desert Camo, Centra front and rear sights, Ken Farrell bases with stripper clip guide, Sinclair hand stop, and Jewell trigger. Gunsmith Neil Keller helped me with the metal work and instructed me on the action work and re-barreling.

Permalink Bullets, Brass, Ammo, Reloading 8 Comments »
August 27th, 2018

How to Expand Cartridge Brass in Stages with Progressive Press

Darrell Jones DJ's Brass Service expanding brass 6mmBR 6BR BRX 30BR Hornady press
Photos from DJ’s Brass Service.

Have you ever expanded a .22 or 6mm cartridge all the way up to .30-caliber? If so, you know this can be a difficult procedure that stresses the case necks and neck-shoulder junction. A significant neck-size expansion done in one big jump can increase run-out, cause doughnuts, or worse yet, even split the brass. Therefore you want to proceed in increments, increasing the neck diameter in stages. One smart way to do that is to use a Progressive Press. This article explains how…

The most successful short-range brenchrest-for-score cartridge is the 30 BR. That cartridge, as well as 30 BR variants such as the 30 BRX, all start with the 6mmBR Norma parent cartridge, typically with Lapua 6mmBR brass. To get a nice 30 BR case you want to expand in stages, increasing the inside neck diameter incrementally from .243 to .308.

Darrell Jones of DJ’s Brass Service creates thousands of 30 BR cases each year. He has found a clever way to speed up the process — Darrell uses a Progressive Press. He runs his 6BR brass through four (4) separate Hornady neck-sizing dies with expander mandrels. First there is a .257 die, followed by .264 (6.5mm), .284 (7mm), and then .308. Then a fifth and final K&M die provides one last, slight expansion so the newly-fashioned 30 BR cases perfectly fit the arbor of Darrell’s neck-turning tool.

So to repeat, the case starts as .243 (6mm), then moves in up stages .257, .264, .284, and .308, with a final “finishing” step prior to neck-turning. You can see the expansion in this video, which starts with 6mmBR brass that was first hydro-formed to 6 BRX:

Watch 6mm Cases Expanded to 30-Caliber (6BRX to 30 BRX)

For this demo video, Darrell expands just one case at a time. However, he can also put multiple cases in the progressive — one per station. This takes a little more effort, Darrell says, but the results are still excellent. Darrell tells us: “I do put multiple cases in the progressive to save time. The results are the same — I just wanted to show a single-step process and how it reduces run-out by not stressing the shoulder with one big expansion from 6mm straight to 30 caliber. Doing the operation in multiple stages avoids binds and helps keep the shoulders concentric.”

This same multi-stage procedure can be use to expand other cartridge types. For example you could take .221 Fireball brass in stages up to .308 to create 300 Blackout brass.

Darrell Jones DJ's Brass Service expanding brass 6mmBR 6BR BRX 30BR Hornady press

Darrell uses caliber-specific, Hornady neck-sizing-only dies with elliptical expanders. Darrell tells us: “The Hornady elliptical expander has a reduced bearing surface that puts less strain on the brass when expanding the necks to the next size.” The fitting at the bottom of the die is the Lock-N-Load die bushing that allows fast die changes.

These particular cases used in the video were first hydro-formed to 6BRX then expanded to 30 BRX before neck turning. DJ’s Brass offers hydro-forming for many popular wildcat cartridges such as 6 PPC, 6mm Dasher, and .284 Shehane.

Darrell Jones DJ's Brass Service expanding brass 6mmBR 6BR BRX 30BR Hornady press

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